Facile Hydrothermal Synthesis of Fe2O3/rGO Composites for Low-Cost Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050162
Author(s):  
Yiping Wang ◽  
Bo Bai ◽  
Qiang Wen ◽  
Pengwei Li ◽  
Huabei Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Low Cost ◽  
Electrode System ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Discharge Current Density ◽  
Transmission Electron ◽  
Facile Hydrothermal Route

In this work, Fe2O3/rGO composites with high capacitive performance were synthesized via a facile hydrothermal route. The morphological and structural characteristics of the synthesized material were obtained by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The three-electrode system was employed for investigating the electrochemical performance in 6 M aqueous electrolytic solution of KOH. The electrochemical data reveals that the Fe2O3/20%rGO shows as high as 171 F g[Formula: see text] specific capacitance at 1 A g[Formula: see text] discharge current density within the operated voltage window −0.9[Formula: see text]V–0[Formula: see text]V, which is 55% higher than that of the bare Fe2O3. After 1000 cycles, the capacity reservation was retained at 74%. The results indicate that the synthesized Fe2O3/rGO material could be a potential candidate for applications in an environmentally friendly commercial electrode.

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

Facile Fabrication of Single Crystalline Fe3O4 Nanorods and its Magnetic Properties

2011 ◽  
Vol 194-196 ◽  
pp. 638-642
Author(s):  
Gui Lian Li ◽  
Xian Ming Liu ◽  
Wei Dong Yin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Measurements ◽  
High Yield ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Single Crystalline ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Facile Fabrication

Single crystalline Fe3O4nanorods were fabricated in high yield via a facile hydrothermal route in the presence of sodium citrate as addition agent. The phase structures, morphologies, and sizes of as-prepared products were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The diameter of magnetite nanorods is about 50~80 nm and its length is more than 2 μm. Room-temperature magnetic measurements showed that Fe3O4nanorods exhibited high saturation magnetization and coercitivity of 77.8 emu/g and 98 Oe, respectively, while the as-obtained nanoparticles had low coercitivity value.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

scholarly journals Towards Iron-Titanium Oxide Nanostructures from Ecuadorian Black Mineral Sands

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Low Cost ◽  
Mineral Resources ◽  
Added Value ◽  
Secondary Phases ◽  
Hydrothermal Route ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Pre Treatment

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.

PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites

2011 ◽  
Vol 1292 ◽  
Author(s):  
Dengrong Cai ◽  
Jianmin Li ◽  
Shundong Bu ◽  
Shengwen Yu ◽  
Dengren Jin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Peg 400 ◽  
Transmission Electron ◽  
Light Region ◽  
Facile Hydrothermal Route ◽  
Degradation Ratio

ABSTRACTA facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions.

scholarly journals Perovskite CsPbBr3 Quantum Dots Prepared Using Discarded Lead–Acid Battery Recycled Waste

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1117 ◽  
Author(s):  
Lung-Chien Chen ◽  
Ching-Ho Tien ◽  
Sin-Liang Ou ◽  
Kun-Yi Lee ◽  
Jianjun Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Storage Batteries ◽  
Recycled Waste ◽  
Cspbbr3 Quantum Dots ◽  
Very High ◽  
Lead Acid

Perovskite CsPbBr3 quantum dot (CsPbBr3-QD) recovery was performed using lead scrap from lead storage batteries. The perovskite CsPbBr3-QD characteristics were analyzed using different PbO/recycled PbO2 ratios. Scanning electron microscopy (SEM) was used to observe the film surface morphology and cross-section. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to observe the perovskite CsPbBr3-QDs’ structural characteristics. A photoluminescence (PL) measurement system was used to analyze the optical properties. The results show that lead scrap from lead–acid batteries as a material for perovskite CsPbBr3-QD production can be successfully synthesized. This saves material and also proves that recycling is valuable. The proposed approach is helpful for future material shortages and materials not easily accessible. Although the efficiency is not very high, this process will be purified using recycled lead in the future to achieve higher quantum yield.

scholarly journals A Novel X-Ray Radiation Sensor Based on Networked SnO2 Nanowires

2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Low Cost ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Sensor ◽  
Sno2 Nanowires ◽  
Radiation Sensors

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.

Characterization and their Fluorescence of Fe3+-Doped La2Zr2O7 Nanocrystals by a Salt-Assistant Combustion Method

2011 ◽  
Vol 306-307 ◽  
pp. 1257-1261 ◽  
Author(s):  
Yun Shan Bai ◽  
Lu De Lu ◽  
Jian Chun Bao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Solutions ◽  
Low Cost ◽  
Combustion Process ◽  
Combustion Method ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Transmission Electron

Nanocrystalline Fe3+-doped La2Zr2O7 series solid solutions were prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results showed the La ion can be partially replaced by Fe ion. The partial substituted products were still single-phase solid solutions and the crystal form remained unchanged. TEM images reveal that the products are composed of well-dispersed square-shaped nanocrystals. The method provides a convenient and low-cost route for the synthesis of nanostructures of oxide materials. The fluorescence of La1.8Fe0.2Zr2O7 nanocrystals was evaluated by the UV-visible absorption spectra and the fluorescence spectra. The results indicate that (LaxFe1-x)2Zr2O7 nanocrystals prepared by this method are a kind of potential fluorescent-emitted material.

scholarly journals Synthesis of V2O3/C composites with different morphologies by a facile route and phase transition properties of the compounds

2014 ◽  
Vol 32 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Yifu Zhang ◽  
Nannan Wang ◽  
Yuting Huang ◽  
Chi Huang ◽  
Xiao Mei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Hydrothermal Route ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Potential Applications ◽  
Subsequent Calcination ◽  
Ft Ir ◽  
First Time

AbstractV2O3 and amorphous carbon composites (V2O3/C composites) with different morphologies (e.g. nanospheres, nanorods and nanosheets) were, for the first time, successfully synthesized by a facile hydrothermal route and subsequent calcination. The as-obtained samples were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometery (EDS), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphology of V2O3/C composites could be easily controlled by varying the reaction time, and, as a result, V2O3/C composites with nanospheres, nanorods and nanosheets were selectively synthesized. Furthermore, the phase transition property of V2O3/C composites was measured by differential scanning calorimetry (DSC), suggesting that V2O3/C composites exhibit the phase transition similar to V2O3, which could expand the potential applications of materials related to V2O3 in the future.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

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